Question

How can you prove that indian constitution reflects the ideas of a secular state??​

Answer 1

WE, THE PEOPLE OF INDIA, having solemnly resolved to constitute India into a SOVEREIGN SOCIALIST SECULAR DEMOCRATIC REPUBLIC and to secure to all its citizens: 
JUSTICE, social, economic and political.
LIBERTY of thought, expression, belief, faith and worship.
EQUALITY of status and opportunity, and to promote among all;
FRATERNITY assuring the dignity of the individual and the unity of the Nation"
IN OUR CONSTITUENT ASSEMBLY this 26/11/1949, do HEREBY ADOPT, 
ENACT AND GIVE TO OURSELVES THIS CONSTITUTION'.

Answer 2

We Can say that as in our country there is No National Language, No National Religion . Also as  most of our states are divided on the basis of their language and religion and yet our country stands strong this shows that how constitution of our country supports secularism, We all have Right to Chose our Religion  too.